Note : V3 will not charge by simply supplying 5V through USB (it's possible to use common USB cable for charging if you are using Motorola special PC driver software).
Motorola uses the pin between Pin #3 and #4 (Pin X) to sense what device is attached to the mini-USB port. Shorting Pin #3 to #2 and #X causes the phone to go into handsfree/carkit mode and the LCD backlight will ignore timeout settings and stay on.
Shorting pin X to pin 1 via R=200KOhm and to pin 4 via R=200KOhm causes the phone to go into charge mode.COMMENTS: